To allow UptimeMonster IP addresses (2a01:4f8:c012:9c4a::1 IPv6 and 162.55.41.109 IPv4) in Apache, you will need to modify your Apache configuration file. Here’s how you can do it:

1. Access the Apache Configuration File

Open your Apache configuration file using a text editor. The main configuration file is typically located at /etc/apache2/apache2.conf or /etc/httpd/httpd.conf. Alternatively, you might need to edit a specific virtual host configuration file under /etc/apache2/sites-available/ or /etc/httpd/conf.d/.

sudo nano /etc/apache2/apache2.conf

Or, for a specific virtual host configuration file:

sudo nano /etc/apache2/sites-available/your-site.conf

2. Add IP Allow Rules

Inside the appropriate <Directory>, <Location>, or <VirtualHost> block in your Apache configuration file, add the Allow directives for the specified IPv6 and IPv4 addresses.

<Directory /var/www/html>
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted

    # Allow specific IPv6 address
    Allow from 2a01:4f8:c012:9c4a::1

    # Allow specific IPv4 address
    Allow from 162.55.41.109
</Directory>

3. Save and Close the Configuration File

After adding the Allow directives for the IP addresses, save the changes and close the editor. In nano, press CTRL + X, then Y to confirm, and Enter to save.

4. Test Apache Configuration

It’s important to check the syntax of your Apache configuration files to ensure there are no errors:

sudo apachectl configtest

If the test is successful, you should see Syntax OK.

5. Restart Apache to Apply Changes

Finally, restart Apache to apply the new configuration:

sudo systemctl restart apache2

Or, for older systems using init.d:

sudo service apache2 restart